Comparison of the effectiveness and safety of dronedarone and amiodarone for preventing recurrence after catheter ablation of atrial fibrillation: an open-label randomized controlled trial.

BACKGROUND: The high recurrence rate after catheter ablation for atrial fibrillation (AF) remains a challenge. Short-term antiarrhythmic drugs are commonly used during the 3-month blanking period, but the choice between amiodarone and dronedarone is unclear. OBJECTIVES: This trial directly compared the effectiveness and safety of dronedarone versus amiodarone administered during the blanking period post-ablation in AF. METHODS: In this open-label, randomized controlled trial, 280 patients undergoing AF ablation were assigned to receive 12 weeks of treatment with either dronedarone or amiodarone, which was discontinued upon completion of this treatment phase as per protocol. The primary endpoint was atrial tachyarrhythmia recurrence (>30 seconds) after the blanking period. RESULTS: A total of 280 participants were enrolled, of whom 273 were included in the modified intention-to-treat (mITT) analysis. In the mITT analysis, recurrence rates were not significantly different between the dronedarone and amiodarone groups (23.4% vs. 16.9%, P=0.184). Secondary efficacy endpoints also showed no significant differences. However, the dronedarone group had a significantly lower incidence of side effects (40.9% vs. 64.0%, P<0.001), primarily due to fewer cases of QTc-interval prolongation (5.8% vs. 15.4%, P=0.01) and hypothyroidism (8.8% vs. 26.5%, P<0.001). The intention-to-treat analysis, which included all enrolled participants, yielded results consistent with those of the mITT analysis. CONCLUSIONS: Therapy with dronedarone during the blanking period after AF ablation was associated with a similar recurrence rate but a superior safety profile compared to amiodarone.